CVE-2026-39963

Source
https://cve.org/CVERecord?id=CVE-2026-39963
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39963.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-39963
Aliases
Published
2026-04-14T23:31:13.843Z
Modified
2026-08-07T11:50:45.613284183Z
Severity
  • 6.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N CVSS Calculator
Summary
Serendipity: Host Header Injection enables authentication cookie scoping to an attacker-controlled domain
Details

Serendipity is a PHP-powered weblog engine. In versions 2.6-beta2 and below, the serendipitysetCookie() function in include/functionsconfig.inc.php uses $SERVER['HTTPHOST'] without validation as the domain parameter of setcookie(). An attacker who can influence the Host header at login time, such as via MITM, reverse proxy misconfiguration, or load balancer manipulation, can force authentication cookies including session tokens and auto-login tokens to be scoped to an attacker-controlled domain. This enables session fixation, token leakage to attacker-controlled infrastructure, and privilege escalation if an admin logs in under a poisoned Host header. This issue has been fixed in version 2.6.0.

Database specific
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-565"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39963.json"
}
References

Affected packages

Git / github.com/s9y/serendipity

Affected ranges

Type
GIT
Repo
https://github.com/s9y/serendipity
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
Database specific
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.6.0"
        }
    ],
    "cpe": "cpe:2.3:a:s9y:serendipity:*:*:*:*:*:*:*:*",
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

2.*
2.1-beta1
2.1-beta2
2.1-beta3
2.1-rc1
2.1.0
2.1.1
2.2.1-alpha1
2.3-beta1
2.3-rc1
2.3.0
2.4-beta1
2.4.0
2.5-beta1
2.5.0
2.6-beta1

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39963.json"